In this paper, the luminescent properties of rare earth containing polyoxometalates were investigated by combining theory with experiment.Firstly, a series of rare earth containing polyoxometalates clusters Na9LnW10O36 (Ln 3+ = Sm 3+ , Eu 3+ , Tb 3+ , Dy 3+ ) were synthesized by the conventional aqueous solution synthesis method.Secondly, the structure of clusters was characterized by powder X-ray diffraction, FTIR spectroscopy and Raman spectroscopy.Finally, the optical properties of the clusters were investigated by UV-Vis spectra and fluorescence spectra.Through systematic experiments, students have a comprehensive and profound understanding of the structure characterization and luminescence properties of rare earth clusters.

为了提高学生对大型仪器在化合物结构表征、 性质研究及实际应用能力,利用水溶液回流法合成了Dawson型多酸(NH4)6 P2 Mo18 O62,并利用FTIR、Raman、UV-Vis与CVs对多酸的结构与光电活性进行研究;分别用UV-Vis光谱及动力学法对维生素C光谱检测的检出限、检测范围、响应时间、选择性及可重复使用性进行研究;通过系统性实验训练全面培养学生综合设计、科研创新、实际应用等能力.

Based on the functional complementarity between the reversible electrochromic property of the Dawson type polyanions P2W18O626- and the excellent luminescent property of Tb3+, the reversible electrochromic and luminescent switching properties of P2W18O626-@TB3+ mixed solution were achieved under redox potential stimulation. The effects of applied reduction potential on electrochromic response time and the energy transfer efficiency of luminescent switch were investigated. And the energy transfer efficiency of the mixed solution P2W18O626-@Tb3+ were 85.97%, 87.53% and 93.42% when applied different reduction potential -0.38, -0.69 and -0.85 V, respectively. On this basis, the UV-Vis and fluorescence spectroscopy bi-functional detection for H2O2 were realized by combining electrochemical reduction with chemical oxidation methods. The detection limits for H2O2 were 1.76x10(-2) and 3.04 mu mol.L-1 by the UV-Vis and fluorescence spectroscopy, respectively.

Mixtures of W and B 13 C 2 powders were mechanically milled and subsequently annealed at 900–1200 °C. It is found that amorphous W–B–C alloy formed as the mixtures were milled for 20–80 h. After annealing the 80 h-milled mixtures at 900–950 °C, solid solutions of C and/or B in tungsten [W(B, C)], C in tungsten boride [W 2 B(C) or WB(C)] formed by the crystallization of amorphous W–B–C. The formation temperature of W 2 B(C) and WB(C) is lower than that of W 2 B and WB reported previously. As the 80 h-milled mixtures were annealed at 1200 °C, W reacted with amorphous W–B–C completely to form WB and W 2 B 5 or W 2 B 5 instead of the solid solutions of C in tungsten borides, which is determined by the mole ratio of W to B 13 C 2 . The formation mechanisms of the W 2 B(C) and WB(C) solid solutions as well as phase transition rules of the mixtures at annealing temperature and mole ratio were also investigated using first-principle calculation.

随着教育改革的不断深入,高校逐渐改变了以往以学生学习成绩为主要依据的考核方法,文章以无机化学实验课程为例,从预习、课堂提问和讨论、实验操作、实验报告几方面入手,分析了在无机化学实验教学中合理运用多样化考核方法的具体措施.

The red luminescence films [(PEI/P8W48)(m)/PEI/PSS/Ru (phen)/PSS](n) [m = 1, 3, 5; PEI=Poly(ethyleneimine); PSS=poly(sodium 4-styrenesulfonate)] were fabricated by layer-by-layer assembling method based on electrochromic polyoxometalate P8W48 and luminescent complex Ru(phen). The composition and thicking of the films were characterized by UV-Vis spectrophotometry. The electrochemical and luminescent properties were studied by cyclic voltammetry and fluorescence spectrophotometry, respectively. The composite films displayed reversible electrochromic and electroswitchable luminescence properties during redox potential switching. The electrochromic and luminescence switching abilities of the films were almost not changed by double potential steps(-0.85 V/0.85 V) for 50 cycles, suggesting good electrochemical stability of the films.

Surface defects in relation to surface compositions, morphology, and active sites play crucial roles in photocatalytic activity of graphitic carbon nitride (g-C3N4) material for highly reactive oxygen radicals production. Here, we report a high-efficiency carbon nitride supramolecular hybrid material prepared by patching the surface defects with inorganic clusters. Fe (III) {PO4[WO(O2)2]4} clusters have been noncovalently integrated on surface of g-C3N4, where the surface defects provide accommodation sites for these clusters and driving forces for self-assembly. During photocatalytic process, the activity of supramolecular hybrid is 1.53 times than pure g-C3N4 for the degradation of Rhodamine B (RhB) and 2.26 times for Methyl Orange (MO) under the simulated solar light. Under the mediation of H2O2 (50 mmol L-1), the activity increases to 6.52 times for RhB and 28.3 times for MO. The solid cluster active sites with high specific surface area (SSA) defect surface promoting the kinetics of hydroxide radicals production give rise to the extremely high photocatalytic activity. It exhibits recyclable capability and works in large-scale demonstration under the natural sunlight as well and interestingly the environmental temperature has little effects on the photocatalytic activity.

Writing academic papers is one of the basic skills needed by a researcher, and learning to write English articles is compulsory for postgraduates.To improve research ability, you have to be required with the writing skills and put them to practice repeatedly.With the reading habits of English literature, the analysis of discourses, the arrangement of the article structure and the application of the reverse organizing method were demonstrated to illustrate how to cultivate the ability to express views accurately and write English papers on chemistry.

The solvent influences practically all of the physical and chemical properties of the molecular species in solution chemical systems. Although solvent effects have been known for more than a century, they are still difficult to understand and even more difficult to predict. A number of specially designed solvatochromic dyes had been synthe-sized and used as indicators to quantitatively measure the properties of solvents. This review highlights the latest pro-gresses in the past 10 years in the field of solvatochromic fluorescent dyes. Their structure, design idea, synthesis, solvatochromic effects and applications are discussed in detail.

基于金属离子诱导罗丹明螺内酰胺开环反应特性,合成了一种罗丹明酰肼类荧光探针分子RbH.在乙醇-水溶剂中,罗丹明酰肼探针与汞离子作用后吸收光谱出现明显的增强现象,溶液颜色由无色变为粉红;在580 nm处探针溶液具有较强的红光发射,实现了对汞离子的裸眼定性分析和荧光半定量检测.

Organic Chemistry experiment curriculum in colleges and universities is a required course for students majoring in chemistry, this course aims to cultivate students' practice ability and improve student's ability to grasp theoretical knowledge. But with the change of the social situation, the subjects of experiment are too old to stimulate students interest in learning. In this paper, both the problems faced in the organic Chemistry experiment teaching are analyzed in detail, and put forward the organic Chemistry experiment teaching should combine the current research frontier, more emphasis on cultivating students' innovation ability and make students contact more modern science and technology.

The synthesis, photophysical and laser properties of a pyrene-based tetramethyl difluoroboron-dipyrromethane (PYBDP) are reported in the present paper. The PYBDP presents a higher fluorescence quantum yield and Stokes shift than other phenyl-substituted laser dyes in the green region. Under transversal pumping conditions, the new dye exhibits highly efficient and stable amplified spontaneous emissions centering at 531 nm. Moreover, the new dye presents a maximum narrow band ASE lasing efficiency of 10.86% with a wide tunable range (525 nm to 560 nm) on excitation with a Q-switched Nd: YAG (355 nm) laser in toluene.

三苯胺结构单元中,与氮原子相连的3个苯环具有较高的活性、结构多样性和易裁剪修饰的特性,因此通过在苯环适当的位置外接不同的识别基团,可得到一系列具有特定传感性能的三苯胺类荧光探针分子.系统总结了三苯胺衍生物在金属离子、阴离子和小分子检测中的研究进展,并对探针分子的设计思路、合成方法、应用范围等进行了详细的比较分析,同时对其未来的发展趋势进行了展望.

This research tested the inhibition activity of two siple dosages of dimethomorph and azoxystrobin and their different proporation mixtures against Alternaria solani.As the results,these siple dosages exhibited activity at the concentrations of 800.0 mg/L and 800.0 mg/L with the inhibition ratios of 83.64 % and 80.77 %,respectively.The EC50 values were 274.0 mg/L and 161.4 mg/L.However,the mixture of dimethomorph/azoxystrobin expressed germicidal efficacy with the inhibition ratio of 82.76 % and EC50 value of 140.0 at the proporation of 1∶10.By comparison,the EC50 of the mixture was far less than that of the siple dosages.The results indicated that the mixture of dimethomorph/azoxystrobin greatly reduced the resistance risk of dimethomorph.

Taking taxol as a standard sample,a separation condition was established to determine the anti-tumor active taxol content in the extracts of the fresh leaves and barks of taxus.The chromatography conditions were: chromatographic column: C18,Φ 4.6 × 250 mm,flowing solvent: methanol︰water︰acetone nitrile = 45︰35︰20,examination wave length: 225 nm,column warm: room temperature,speed of flow: 1.0 mL/min.The result indicated that the contents of taxol in the bark is higher than that in the leaf.

With the combination of the microwave digestion and ICP-AES, and by optimizing the instrument conditions, the micro digestion-ICP-AES method for the determination of eight metal elements, Zn, Fe, Ca, Mn, K, Mg, Sr and Na, in Mongolian medicines has been established. This method works by determining one solution sample with many kinds of elements at one time. The average recovery of the method is between 92.2% and 113.3% and the RSD is between 0.4% and 3.2%. The accuracy and precision of the method was tested by comparing the values of GBW070602. The determination results were found to be basically consistent with the reference values, which means the test result is reliable.

Amorphous BCN was prepared by chemical solid-state reaction between boracic acid (H3BO3) and melamine (C3N6H6) in mass ratios of H3BO3 to C3N6H6 of 1:2–1:4 and heat treatment at 1273K under 10−3Pa. The amorphous BCN behave insulating property below 890K, but semiconductor conductivity above 890K and show different conductivity–temperature relationships in temperature ranges of 913–963 and 963–1083K. The conductive activation energy was calculated to be 0.26–0.34eV at 913–963K and 1.02–1.10eV at 963–1083K, implying that the conduction mechanisms are different in the different temperature ranges. Annealed for 40min at 1473K under 4.0GPa, the amorphous BCN with the chemical composition B0.48C0.29N0.23 was prepared in the mass ratio of 1:3 crystallizes into single-phase hexagonal (h-BCN) compound with lattice constants of a=0.2506nm and c=0.6652nm. Raman scattering peaks were observed at 1330, 1364,1584 and 1617cm−1 in the Raman spectrum (RS) of h-BCN, of which the peaks located at 1330 and 1617cm−1 are assigned to characteristic peaks of the h-BCN.

Amorphous BCN was prepared by ball milling the mixture of graphite and hexagonal BN for 120h, and then annealed for 45 min. at 1600K under 4.5GPa. The XRD，TEM and Raman scattering measurement indicated that the as-prepared sample consists of hexagonal phase Ⅰ with lattice constants a 1 =0.2551nm and c 1 =0.6716nm and hexagonal phase Ⅱ with lattice constants a 2 =1.2360nm and c 2 =0.8570nm, of which the hexagonal phase Ⅱ is an unknown phase of boron carbon nitride. Three characteristic Raman peaks located at 1279, 1368 and 1398cm -1 respectively, were observed in the Raman spectra recorded at room temperature. The temperature dependent Raman scattering spectra of the sample were taken at temperature ranging from 93 to 673K.The measuring results indicate that the hexagonal phase of Ⅰ mainly exist in the sample at 93K and hexagonal phase of Ⅰ convert to hexagonal phase of Ⅱ completely when at above 473K.The phase transition from the hexagonal phase of Ⅰ to Ⅱ occurs with increasing temperature, vice versa. The mechanism of the phase transition is discussed in the present work.